Enhancement in photovoltaic performance of perovskites solar cells through modifying the electron transport layer with reduced graphene oxide

•The rGO layer below the ETL improve the performance of perovskites solar cells.•The rGO layer accelerate charge transport at perovskites/ETL interface.•The rGO layer suppress the recombination losses at perovskites/ETL interface. Herein, the electron transport layer (ETL) ZnO in perovskites (PVSK) solar cells (PSCs) has been modified using reduced graphene oxide (rGO) and investigated its impact on the photovoltaic (PV) performance of PSCs. The device with rGO exhibits enhanced performance with a power conversion efficiency (PCE) of 17.08% as compared to the device without rGO layer (15.93%). The improved device performance of rGO-based device is attributed to the faster charge transfer at the PVSK/ETL interface confirmed via steady-state photoluminescence (PL) and time-resolved photoluminescence (TRPL) spectra. The evaluated PV cell parameters indicate that the rGO layer suppresses the recombination losses and accelerates the charge transport in PSCs.